Republicans in the U.S. Congress are demanding to know how much the White House influenced the Federal Communications Commission while the agency crafted Net neutrality rules.

The FCC has until Monday afternoon to produce unredacted email messages, focused on Net neutrality rules, between FCC staff and officials with President Barack Obama's administration, Representative Jason Chaffetz said in a letter to the FCC Friday. The Utah Republican is chairman of the House of Representatives Oversight and Government Reform Committee.

Chaffetz's committee is "investigating the potential involvement of the White House" in the creation of proposed Net neutrality rules that the FCC is scheduled to vote on next Thursday, he said in the letter. FCC Chairman Tom Wheeler will propose regulations that would reclassify broadband as a regulated telecommunications service instead of a lightly regulated information service.

An FCC spokeswoman didn't immediately respond to a request for a comment on Chaffetz's letter.

Several congressional Republicans have accused the White House of improperly influencing the FCC net-neutrality rule-making process, after Obama called on the agency to reclassify broadband as a regulated public utility in November. Wheeler appeared to change his position and embrace that idea after the president urged the independent agency to do so, critics have said.

But U.S. presidential administrations have repeatedly weighed in on FCC proceedings during the past 30-plus years, Net neutrality advocate Public Knowledge has noted.

Chaffetz's letter to the FCC came just two days after Republican leaders of the House Energy and Commerce Committee told Wheeler they were expanding an investigation into agency rule-making processes.

The Energy and Commerce Committee's probe covers a wide range of FCC process concerns beyond Net neutrality, but new reports detailing White House contact with the FCC on Net neutrality raise "additional concerns about whether the commission is managing its affairs with the independence and openness required by its mandate," committee leaders said in a Wednesday letter to Wheeler.

Republican concerns about Obama administration influence over the FCC were fueled by a Feb. 4 Wall Street Journal report saying the White House last year had set up a "parallel version of the FCC" to push for regulation of broadband providers.

Chaffetz's letter asks for specific email messages sent by Obama administration officials to the FCC in April. On Friday, Vice.com published an exchange between administration officials and FCC staff that the website obtained through a Freedom of Information Act request.